<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<style>
  div{
    background-color: green !important;
  }
  #d1{
    color: red;
    background-color: blue;
  }
</style>
<body>
<div id="d1">
  <p>这是p标签</p>
  <span>这是span</span>
  <a href="">这是超链接</a>
</div>
</body>
</html>